Automatic reset circuit breaker



Sept- 1, 1935- w. H. FRANK 2,053,247

AUTOMATIC RESET CIRCUIT BREAKER Filed April 21, 1933 2 Sheets-Sheet 1 |1||' l HHH HHH mumll HILLI/ Wea ATTORNEY Sept. 1, 1936. w H FRANK 2,053,247

AUTOMATIC RESET CIRCUIT BREAKER Filed April 21, 1935 2 Sheets-Sheet 2 22 Illu* 25 3o 49 INVENTOR.

FJ' Q E ad www ,ld/@Az 0M wwf --M ATTORNEY.

Patented Sept. l, 1936 PATENT oFFlcE AUTOMATIC RESET CIRCUIT BREAKER William H. Frank, Detroit, Mich., assignor to Bulldog Electric Products Company,

Mich., a corporation Application April 21,

23 Claims.

This invention relates to circuit protective devices known as circuit breakers, and aims particularly to provide means for automatically resetting such devices after overload release.

In order to aid inthe-understanding of the desires and aims of the invention, a cursory review of the history of circuit protective devices will be given.r

For years, fuses have been used as circuit protective devices. The use of fuses has been found to be objectionable because of the fact that replacement of a blown fuse is usually accompanied with considerable difficulty, due in part, to the fact that the person in charge must make his way toO the fuse box, usually in darkness, must find a fresh fuse for replacement, must proceed to nd out which of the large number of fuses in the box is the blown fuse, and then must proceed to replace the blown fuse with the fresh fuse. All this difficulty is encountered every time a fuse blows, whether the overload condition which caused the fuse to blow was a momentary one or a continuing one.

Further, replacement ofa blown by a fresh fuse may be ineffectual and annoying if the overload or sho'rt circuit is still on the line,

because the fresh fuse will immediately blow.

As a solution, it has been contemplated to use manually resettable circuit breakers as circuit protective devices. The provision of these devices eliminates much of the dfiiculties encountered in restoring the circuit after an overload or short circuit, but even when such devices are provided it becomes necessaryon the release of a circuit breaker due to overload, forthe person in charge still to make his way in darkness to the panel of protective devices; namely, the circuit breakers, to fumble around and find out which breaker has tripped, or released, and then to reset the tripped breaker.

As a more satisfactory solution, this invention aims to provide automatically resetting protecting devices, such as circuit breakers. When such devices are provided, an overload, momentary or otherwise, will cause a release of the breaker, for -circuit protection. However, the breaker will, after a short time interval, be reset automatical- 1y, and without the aid of the person in charge. If the overload which caused release is but a momentary one, as is commonly the case, the circuit, once reestablished automatically, will remain reestablished, and the only inconvenience will be a momentary condition of darkness dur 4 ing the time that the ruptured circuit was being recstablished. The provision of such devices,

Detroit, of West Virginia 193s, serial No. 667,149

(Cl. zoo-116) therefore, eliminates the necessity of the person in charge going to the circuit control box and attempting to reestablish manually a ruptured circuit.

The provision of automatically resetting circuit breakers is rendered somewhat more desirable when such breakers are equipped with certain auxiliaries for providing other operations and functions tol the breakers. For example, the breaker can be equipped with means whereby the circuit, once reestablished, can be ruptured again and immediately, if the overload continues, and the provision of such means on an automatically resetting breaker provides repeated and successive cycles of breaker release and breaker reset, so long as the overloadicontinues. a

However, inasmuch as this would be of damage to the breaker itself, due to burning out the breaker contacts, and due to the unwinding of the breaker spring motor, if a spring motor is used, the breaker can be provided with a personally controllable means whereby the person in charge can manually maintain the breaker parts in open circuit position, so long as the overload continues. The provision of such means, hereafter referred to as a manual reset latch, therefore permits the person in charge to maintain the circuit open, so that he may investigate the cause of the breaker release, and may eliminate such cause by repairing the damaged or inlured part of the circuit. I The means is operated manually to prevent the automatic resetting means from functioning to close the circuit, and when it is operated, the person in charge must reset the device manually to close the circuit.

Another auxiliary, which has been found to be of value in connection with circuit protective devices, is a manually operable control whereby the operator can open or close the circuit at will. This auxiliary operates as an accessory to the device and the automatic operation thereof is not eliminated or minimized.

It will be observed at the present time that the construction of the manual control here provided is such that it' does not and cannot interfere with automatic release or trip of the circuit breakers on the arising. of an overload or short circuit, and for this reason the circuit breakers of the instant application may well be considered trip free.

In theY instant application, several forms of circuit breakers are disclosed and these have in general, a thermal holding and releasing currentresponsive element and a spring mechanism which operates in general as follows: Normally a stop on the thermal element holds the breaker parts r in on position, against the influence of the spring. On the arising of an overload, the thermal element warps and releases the parts, which are then moved by the spring to off position, there being held by a second stop on the thermal element, against the influence of the spring, this stop engaging the breaker parts only when the thermal element is in its warped position. When the thermal element has cooled sumciently, that is to say, in a moment or two, the thermal element releases the breaker parts and the spring moves them to on position once more, to be held by the first mentioned stop.

If the overload no longer exists the cycle of movements will end at this time.` However, if the overload or short circuit persists, the thermal element will warp again and the cycle will be repeated, being repeated until, (a) the overload goes oif the line; (b) or until the line is opened through an auxiliary switch; (c) or untilthe spring has run down so as to be too weak to move the parts; (d) or until the manual reset latch, provided, is operated to maintain the circuit open.

It is observed, at the present time, that I am not the rst to disclose an automatically resetting circuit protective device. However, I am the iirst to provide an inexpensive, suitable, and satisfactory device of the character specified, as will more presently appear.

Still further objects of the invention will be more specifically brought out and will presently appear upon reference to the following detailed description of an embodiment of the invention, disclosed in the appended drawings forming a part of this application. In these drawings,

Fig. 1 is a top plan view of an automatically resetting circuit breaker whose current responsive device, or thermal element, moves in a direction parallel to the operating shaft of the breaker, the element functioning directly to release the shaft and trip or reset the breaker.

Figs. 2, 3, 4, and are elevation, end, elevation, and detail sectional views as if on lines 2 2, 3 3, 4 4, and 5 5 of Figs. 1, 2, 1 and 1 respectively, the above figures showing the device as it appears in the on position;

Figs. 6 and 7 are elevation section and end section views of the same device in off position due to overload, and as if on lines 6 6, 1 1 of Figs. 'I and 6 respectively;

Figs. 8 and 9 are similar views of the device in off position, due to manual control operation, and as if on lines 8 8, 9 9 of Figs. 9 and 8 respectively;

` Fig. is an elevational section ofthe device in an off position, due to operation of the manual reset latch.

There is also included in the drawings three figures which show diagrammatically the breaker operation.4 Of these figures,

Fig. A shows parts in on position;

Fig. B shows parts in ofl!" position; and

Fig. C shows how manual control operation can be effected.

Basic aspect o! the mechanism: Figs. A, B, and C The fundamental or basic aspect of the mechanism of the invention is best disclosed in Figures A, B, and C, which indicate diagrammatically parts of an automatically resetting circuit breaker, Figure A showing breaker parts in on position, Figure B ,showing breaker parts in of!" or released" position, and Figure C showing how manual control may be effected.

Referring to Figure A, it will be seen that there is disclosed a breaker contact ann I, pivotally mounted at 2, and having a movable contact 3 adapted to engage with or be disengaged from the stationary line contact 4. The arm I is connected to the contact 4 and is connected to the load through a bimetallic, thermally warping element 5. For operating the arm I there is provided an operating shaft 6, having a crank 1, and trunnioned in frame 8, the crank being connected to the arm by a connecting rod 9. Ori one end of the operating shaft is rotatably journalled a drum containing a continuous spring, not shown, which tends to rotate the operating shaft in the direction indicated by the arrow, the combination of the drum and its contained spring being referred to as a spring motor. Formed on the end of the operating shaft 6 is a crank I0 functioning as a holding crank, for acting in opposition to the spring motor. For engaging this crank are stops SI and S2 rigidly connected to but insulated from the thermal element 5, the stop S2 being notched for reasons which will be later brought out.

The operation of the parts so far described, which basically form a complete combination, is as follows: Assume the parts to be in the on" position of Figure A. On the arising of an overload, the thermal element 5 warps away from the holding crank I0 and the stop SI moves away from the crank, releasing the latter and permitting the spring motor to rotate the operating shaft in the direction of the arrow, pulling up on the connecting rod 9 and rupturing the circuit between contacts 3 and 4. The end of the holding crank I 0 engages the tooth of the stop S2, which had been previously out of line with the crank I0 but had been moved into line with the crank I0 in the warping of the thermal element. 'I'he tooth of stop S2 therefore prevents rotation of the operating shaft beyond 180. This condition is maintained for a time interval which will be proportioned to the extent of the f causative overload, due to the heating effective of the latter, and until the thermal element cools and returns to its original position, namely, the position of Figure A. When this happens, the tooth of the stop S2 moves out from under the end of crank I0 and the notch of stop S2 is presented to this end, whereupon the holding crank is released and the spring motor rotates the operating shaft another 180, or until the end of crank Ill engages under and against stop SI The second 180 rotation closes the circuit, by pushing down on the connecting rod 8.

Ii.' the overload which caused opening of the circuit is still on the line, the above recited cycle will be repeated until such a time as the overload disappears ofl' the line, or the spring motor becomes too weak to function. If, however, the overload went oil' the line during the first cycle of operation, the parts come to rest in the on position.

Accordingly, it will be seen from the foregoing, that there has been provided an automatically resetting circuit breaker including means, (a motor) which continuously tends to move the contact arm to and from contact making position, the operation of the means being controlled by a pair of selectable stops on a current responsive element, namely, the thermal element, which is so connected to the line that its condition is affected by the condition of the line.

For a more complete and detailed description of a circuit breaker constructed in accordance with the ideas expressed above and disclosed in Figures A and B, reference may be had to the detailed description of Figures 1 to 10, which figures disclose practical and operative circuit breakers, fundamentally like that of Figures A and B.

In Figure C, there is disclosed fundamentally and diagrammatically, the manual control operations.

The thermal element is mounted on a slide block ySB in the base of the device, and this block may be moved to bring the "on stop SI or the off stopV S2, selectively into registration with the path of the holding crank I0, by a handle H;

the reciprocation of the thermal element and the block, as a\unit, having the same enect as the movement ofthe upper end of the element alone, due to warping.

It will be here noted that the manual control operation is eiected by moving the block or mounting for the thermal element, and not by warping the element manually; this is done so that manual control does not prevent automatic tripping, and so that the device will be trip-free.

Further, while the'biasing means for the contact arm is shown to be a spring motor, other means might well be used as an alternative.

The breaker of'Figs. 1-10 The automatically resetting breaker of these figures is characterized by the fact that the thermal element moves in the direction of the operating shaft, and functions directly thereon to release it for trip and reset of the breaker.

The breaker parts are mounted upon a base II of insulating material and are enclosed within a sealed cover, also of insulating material, the cover having slots through which project the three manually engageable parts of the breaker, namely, the winding drum I2, the manual control lever or handle I4, and the manual reset latch lever or handle I5. The breaker parts will now bedescribed specifically.

Pivotally mounted on an axle pin I6, to and between the upstanding fixed frame plates I1. is the breaker contact arm I3, having a contact i3 for engaging the xed line contact 20 of the breaker. Pivotally connected by an axle pin 2| to two upstanding parts of the breaker contact arm I8 are connecting rod links 22 which at vtheir upper endsA ,are connected to a crank 23 formed on the breaker operating shaft 24, the latter being trunnioned in aligned holes of the upstanding frame plates. I 1. It is observed that rotation of the operating shaft 24 operates, through the mediumof the crank 23 and the connecting rod links 22, to move the contact arm to and from contact making and breaking position.

One end of the operating shaft is bent perpendicularly from the axis of the shaft to provide a holding crank 25, adapted to be held by one or another of the stops provided on the thermal element, referenced generally T. The latter is connected at one end, by a flexible lead, to contact arm I8, and at the other, to the load.

The on holding stop, that is to say, the stop which holds the holding crank 25 in the on" position, Figs. 1-4, is referenced 26, and is in the nature of a lug provided on plate 2l which bridges the upperends of the relatively electrically connected upstanding thermal bimetallic warping strips 28 of the element T, and is insulated from these strips by an insulating Vstrip 23.

The other stop, that is to say.4 the stop which holds the crank 25 in the oir position, Figs. 6-9, is referenced 30, and is also in the nature of a block of insulating material 33, disposed in a depression in the upper surface of the base and so proportioned as to be able to slide in such depression, in a direction parallel to the axis of the operating shaft 24. 'I'he block and the depression have cooperating grooves and keys 33a providing runways for the block.

For manually sliding the block 33 in its depression, there is provided an actuating device whose handle has previously been referred to as a manual control handle I4. 'I'his handle is journalled in the base on the end of a crossshaft 34, which shaft is provided with an upstanding finger 35 engaging in a notch in the lower surface of the block 33, and it will be observed that movement of the actuating handle I4 rotates the shaft 34 and slides the block 33 in its depression. For latching the handle I4 in the on position of Fig. 3, or in the ofi' position of Fig. 9, there is provided a spring 31 adapted to engage one or another of a pair of notches 36, formed in that part of the handle near the shaft 34. Y

0n the end of the operating shaft opposite that end thereof which is formed as `a holding crank 25, is a drum, previously referenced I2, and containing a clock spring 40, wound upon the end of the operating shaft and having one end xed to the shaft and the other end fixed t-o the drum at 4I. This spring is the biasing means for the movable contact arm and tends to '1, 1931, now Patent No. 1,952,039,- oi' March 20,

For winding the spring, the user rotates the drum, which is rotatably journalled on the shaft, and is held against reverse rotation by a. ratchet wheel 43, fixedJ to thedrum and disposed between aframe plate Il and the drum, as indicated in Fig. 3. A clockwork pawl 44 co-operates with the ratchet to prevent movement of the drum in the counter-clockwise direction as the drum is being rotated clockwise to wind the sprlng,'it being observed 4that the drum can be wound by moving it with the thumb, as can readily be seen from Fig. 2.

In order to' provide a manual reset latch, which maintains the breaker open and requires that the breaker be closed manually. or manually reset. there is slidably mounted on one of the upstanding frame plates I-l, a plate 41, guided on the upstanding frame plate through the medium of the slots receiving pins 43 projecting from the frame. 'I'he latching plate is formed with an extension 6| adapted to be moved with the plate, to underlie the notch 3i and when so moved, to prevent rotation of the holding crank 25 from the on' position to the on position. The spring 52 co-operates with notches 53 in the lower edge of the plate 41 to define positions of the latter.

The operations of the breaker of Figs. 1-10 will now be described in complete detail. Assume the parts to be in on position. At this time the holding crank 25 engages and is disposed under the on stop 26 and the operating shaft and its associated parts are held in the on position, with the contact arm I8 in a horizontal position, so that contact I9 engages contact 20, the parts being held against the influence of the spring 40 which tends to rotate the operating shaft clockwise.

It is observed that the thermal element T occupies such a position on normal load that the stop 26 is directly in line with holding crank 25.

Upon the arising of an overload, the thermal element T will warp in the direction of the axis of the operating shaft 24, that is to say, towards the right of Fig. 3, suiiiciently to move stop 26 away from the holding crank 25. The spring 40 consequently rotates the parts clockwise with an extremely rapid movement. Such rotation causes an upward pull on the connecting rod links 22 and pivots contact arm I8 to the position of Fig. 6 from the position of Fig. 2; that is to say, it opens the circuit. When the thermal element T Warped to the right of Fig. 3, it placed tooth 3Ia in line with the crank 25. Consequently the crank rotates on overload but one-half turn and is engaged by the top of tooth 3| a, to restrain further rotation of the parts.

When the circuit has been opened suiciently long for the-thermal element T to cool and warp back to its original position, the tooth 3Ia, will move away from crank 25 and notch 3l will be placed in line with this crank. Accordingly, the operating shaft will be free to rotate, and the spring 40 will rapidly rotate the shaft another half turn clockwise to close the circuit and to bring holding crank 25 once more under and against stop 26.

If the overload still is on the line, this cycle of operations will be repeated and the repetition will continue so long as the overload is in existence or until the spring 40 has been run down to such an extent that it can no longer rotate the parts, or until the breaker is held open by operation of the manual control means or the manual reset latch. It will consequently be seen that the circuit breaker automatically resets itself after having been opened on overload.

For manual control operation, the actuating handle I4 is utilized. lf the breaker is to be moved from the on position,`Fig. 3, to the off position, Fig. 9, the handle I4 is moved from the position of Fig. 3 to the position of Fig. 9. Such movement of the handle causes the block 33 to slide to the right and this movement, carrying the thermal element T with the block, takes the stop 26 out of the path of the 'crank 25 and placesv the tooth 3'Ia in the path of crank 25. The spring 40 rotates the operating shaft to oil position. To restore the parts to on position, the actuating handle is moved back to the position of Fig. 3 which serves to place notch 3| in line with crank 25, freeing the latter and the shaft for movement by the spring 40 which then rotates the shaft until crank 25 is engaged by the stop 26.

In the event it is desired vto latch the breaker in the off position, the manual reset latch handle I5 is moved from the position of Fig. 4 to the position of Fig. 10. Such movement ofthe handle, and obviously of the plate 41, projects the part 5I into a, position directly under the notch 3l. The manual control handle I4 is then moved to olf position and crank 25 rotates, and is held in off position by stop 3Ia. If the control handle I4 is moved back to on position, the circuit will not be closed for the reason that crank 25 is restrained against complete rotation to the on position by virtue of the fact that stop 5I of the manual reset latch is in the path of rotation of crank 25. Further, if while handle I5 is in the latching position, the thermal element returns on cooling, this will not permit the shaft, to rotate to on position, for the latch will be engaged by crank 25. In other words, after the latch is once operated, reset can occur manually only.

If it becomes necessary to wind the spring 40, the drum I2 may be rotated by the operator manually, and this action winds the spring Without rotating the operating shaft, the winding being and connecting rod, means constantly tending to rotate said shaft and cause said arm to move positively to and from on and off positions, successively and repeatedly and circuit responsive means operatively connected to the controlled circuit for controlling the operation of the shaft rotating means.

2. An automatically releasing and resetting circuit protecting breaker including a contact arm, an operating shaft connected thereto by a crank and connecting rod, means constantly tending to rotate said shaft and cause said arm to move to and from on and off positions, successively and repeatedly, and stop means for said shaft including diametrically opposite selectable stops on opposite sides of said shaft, one of which moves out of stopping position automatically on the arising of an overload, with the other moving into stopping position at that time, the shaft rotating at that time, the stops being constructed to move automatically, after a time interval, so that the second mentioned one moves out of stopping position and the first mentioned one moves into stopping position, the shaft rotating a second 180 at that time.

3. An automatically releasing and resetting circuit protecting breaker including an operated member having a constant tendency to move to and from on and off positions, successively and repeatedly, and means energized on a. circuit abnormality and thereafter automatically de-energized for controlling the movement of said meml ber, so that the latter will go thru successive and member having a constant tendency to move to and from on and of! positions, successively and repeatedly, and means energized on a circuit abnormality and thereafter automatically de-energized for controlling the movement of said member, so that the latter will go thru successive and repeated cycles of movement, stopping in each of its two positions momentarily, at least, so long as there exists an abnormality in the circuit connected to said means, and manually controllable means operating on said controlling means for manually moving said member to and from on and oi positions, as desired.

5. An automatically releasing and resetting circuit protecting breaker including an operated member having a constant tendency to move to and from on and off positions, successively and repeatedly, and means energized on a circuit abnormality and thereafter automatically de-energized Afor controlling the movement of said member, so that the latter will go thru successive and `repeated cycles of movement, stopping in each of its two positions momentarily, at least, so long as there exists an abnormality in the circuit connected to said means, and manually controllable means for latching said member in off position and thereby prevent automatic reset, and manually controllable means for operating on said controlling means for manually moving said member to and from on and off positions, as desired.

6. An automaticallyA releasing and resetting circuit protecting breaker including an enclosing casing, a movable circuit closing member, a spring motor providing therefor a constant tendency towards cyclic movement to and from released and reset positions, and a circuit responsive control means for controlling the cyclic movement of said contact in release and reset cyclesand manually operable means accessible externally of said casing for rupturing or establishing said circuit independently of the influence of the control means, the motor having rewinding means externally accessible through the casing.

'1. An automatically releasing and resetting circuit protecting breaker including an enclosing casing, a movable circuit closing member, a spring motor providing therefor a constant tendency towards cyclic movement to and from released and reset positions, and a circuit responsive control means for controlling the cyclic movement of said contact in release and reset cycles, and manually operable means accessible externally of said casing for rupturing or establishing said circuit independently of theinfluence of the control means, the motor having rewinding means impositively connected to said member to assure trip free operation thereof and externally acmanually operable means accessible externally of said casing for rupturing or establishing said circuit independently of the influence of the control means, the motor having rewinding means in the nature of a drum and externally accessible through the casing.

9. An automatically releasing and resetting circuit protecting breaker including a sealed casing containing a movable circuit closing member, means providing therefore a constant tendency towards cyclic movementto and from released and reset positions, a circuit responsive control means Within the casing for controlling the cyclic movement of said member in release and reset cycles, the control means being automatically shiftable for release and reset, and manually operable means outside the casing for shifting the control means for release and reset.

10. .An automatically releasing and resetting circuit protecting breaker having a mating contact set, automatically operating parts therefor, and a manually operable switch for supplementing the automatic action of -said parts and operating through said contact set and certain of said operating parts.

11. An automatically releasing and resetting circuit protecting breaker having a circuit responsive control means, a mating contact set, and operating parts therefor, controlled by said control means, and a manually operable switch for supplementing the automatic action of said parts and operating through said contact set and certain of said operating parts, said switch haxing a member manually operable for moving said control means.

12. An automatically releasing and resetting circuit protecting breaker having a circuit responsive control means, a mating contact set, and operating parts therefor, controlled by said control means', and a manually operable switch for supplementing the automatic action of said parts and operating through said contact set and certain of said operating parts, said switch having a member manually operable for moving the support of said control means.

13. An automatically releasing and resetting circuit protecting breaker including a mating contact set, automatically operating releasingand resetting mechanism therefor, a circuit responsive automatic control therefor, and means for overcontrolling the automatic control, said means being manually operable for preventing automatic reset operation of the aforesaid mechanism subsequent to an automatic release operation thereof.

14. An automatically releasing and resetting circuit protecting breaker including mating contacts, automatically operating releasing and resetting mechanism therefor, a circuit. responsive automatic control therefor, and means for overcontrolling the automatic control, said means being manually operable for preventing automatic reset operation of the aforesaid mechanism subsequent toan automatic release operation thereof, the means being manually operable at any stage of the functioning of the mechanism, even prior to any automatic release operation thereof.

15. An automatically releasing and resetting circuit protecting breaker including mating contacts, automatically operating releasing and resetting mechanism therefor, a circuit responsive automatic control therefor, and means for overcontrolling the automatic control, said means being manually operable for preventing automatic reset operation of the aforesaid mechanism subsequent to an automatic release operation thereof, the means being manually operable at any stage of the functioning of the mechanism,

even prior to any'automatic release operation thereof, and without interfering with automatic release operation thereof.

16. An automatically releasing and resetting circuit protecting breaker including mating contacts, automatically operating releasing and resetting mechanism therefor, a circuit responsive automatic control therefor, and means for overcontrolling the automatic control, said means being manually operable for preventing automatic reset operation of the aforesaid mechanism subsequent to an automatic release operation thereof, the means being manually operable at any stage of the functioning of the mechanism, even prior to any automatic release operation thereof, and without interfering with or causing automatic release operation thereof.

17. An automatically releasing and resetting circuit protecting breaker including mating contacts, automatically operating releasing and resetting mechanism therefor, a circuit responsive automatic control therefor, and means for overcontrolling the automatic control, said means being manually operable for preventing automatic reset operation of the aforesaid mechanism subsequent to an automatic release operation thereof, the means being manually operable at any stage of the functioning of the mechanism, even prior to any automatic release operation thereof, and without interfering with or causing automatic release operation thereof, and a manually operable switch for supplementing the automatic action of said control to accomplish release and reset manually, if desired, said switch including said contacts and parts of said mechanism.

18. An automatically releasing and resetting circuit protecting'breaker including mating contacts, automatically operating releasing and resetting mechanism therefor, a circuit responsive automatic control therefor, and means for over-y controlling the automatic control, said means being manually operable for preventing automatic resetoperation of the aforesaid mechanism subsequent to an automatic release operation thereof, the means being manually operable at any stage of the functioning of the mechanism, even prior to any automatic release operation thereof, and without interfering with or causing automatic release operation thereof, and a manually operable switch operable independently of said manually operable reset preventing means, for suppleinenting the automatic action of said control to accomplish release and reset manually, if desired, said switch including said contacts and parts of said mechanism.

19. An automatically releasing and resetting circuit protecting breaker including an enclosing casing, movable means for causing circuit closing, a spring motor providing therefor a constant tendency towards cyclic movement to and from released and reset positions, a circuit responsive control means for controlling the cyclic movement of said circuit closing means in release and reset cycles, and manually operable means accessible externally of said casing for rupturing or establishing said circuit byV causing to be varied the position of the circuit closing means independently of the influence on the control means created by circuit conditions, the motor having rewinding means externally accessible through the casing.

20. An automatically releasing and resetting circuit protecting breaker including mating contacts, automatically operating releasing and resetting mechanism therefor, and means manually operable for preventing automatic reset operation of the aforesaid mechanism subsequent to an automatic release operation thereof, the means being manually operable at any stage of the functioning of the mechanism, even during any automatic release operation thereof.

21. A construction of the character described in claim 2 wherein the stops move in a direction parallel to the axis of the shaft.

22. An automatically releasing and resetting circuit protecting breaker including an operated member having a constant tendency to move to and from on and off positions, successively and repeatedly, and means energized on a circuit abnormality and thereafter automatically de-energized for controlling the movement of said member, so that the latter will go through successive and repeated cycles of movement, stopping in each of its two positions momentarily, at least, s`o long as there exists an abnormality in the circuit connected to said means, and manually controllable means for latching said member in off position and thereby preventing automatic reset, and operable to prevent reset without such operation, by itself, causing release.

23. An automatically releasing and resetting circuit protecting breaker including an operated member having a constant tendency to move to and from on and off positions, successively and repeatedly, and means energized for controlling the movement of said member, so that the latter Will go through successive and repeated cycles of movement, stopping in c ach of its two positions momentarily, at least, so long as there exists an abnormality in the circuit connected to said means, and manually controllable means for latching said member in off position and thereby preventing automatic reset and operable to prevent reset without such operation, by itself, causing release, and manually controllable means for operating on said controlling means for manually moving said member to and from on and off positions, as desired.

WILLIAM H. FRANK. 

